Nicole at One Golden Apple shows you how to make a travel water color kit using an upcycled mint tin and some polymer clay. I love the tip on using fantastix pens which you can fill with water to make watercoloring even more portable without a need for a jar of water.
Nicole writes:

I made this for my 11 year old daughter who is working hard on filling a sketchbook with her best work of black line drawings with the color fill. She brings it with her everywhere so I thought I should make it easy to bring her watercolors along too.